Polycystic kidney disease type 2 protein (IPR003915)

Short name: PKD_2

Overlapping homologous superfamilies


Family relationships



Polycystic kidney diseases (PKD) are disorders characterised by large numbers of cysts distributed throughout grossly-enlarged kidneys. Cyst development is associated with impairment of kidney function, and ultimately kidney failure and death [PMID: 8643665]. Most cases of autosomal dominant PKD result from mutations in the PKD1 gene that cause premature protein termination.

A second gene for autosomal dominant polycystic kidney disease has been identified by positional cloning [PMID: 8650545]. The predicted 968-amino acid sequence of the PKD2 gene product (polycystin-2) contains 6 transmembrane domains, with intracellular N- and C-termini. Polycystin-2 shares some similarity with the family of voltage-activated calcium (and sodium) channels, and contains a potential calcium-binding domain.

Polycystin-2 is strongly expressed in ovary, foetal and adult kidney, testis, and small intestine. Polycystin-1 requires the presence of this protein for stable expression and is believed to interact with it via its C terminus. All mutations between exons 1 and 11 result in a truncated polycystin-2 that lacks a calcium-binding EF-hand domain and the cytoplasmic domains required for the interaction of polycystin-2 with polycystin-1 [PMID: 9326320]. PKD2, although clinically milder than PKD1, has a deleterious impact on life expectancy.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0005509 calcium ion binding

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.